1. The Living Cell Membrane

2. Function Separates the protoplasm from the nonliving environment.
Regulates what enters and leaves the cell.

3. Structure
Here we see a cross section of the cell membrane you should notice two different structures: The phospholipids are the round yellow structures with the blue tails, the proteins are the lumpy structures that are scattered around among the phospholipids

4. Phospholipid
This is a simple representation of a phospholipid. the yellow structure represents the hydrophilic or water loving section of the phospholipid. The blue tails that come off of the sphere represent the hydrophobic or water fearing end of the Phospholipid

5. Phospholipid

6. Proteins
Floating around in the cell membrane are different kinds of proteins. They are not held in any fixed pattern but instead float around in the phospholipid layer. Generally these proteins structurally fall into three categories...

7. Proteins
Carrier Proteins
regulate transport and diffusion

8. Proteins
Marker Proteins
identify the cell to other cells

9. Proteins
receptor proteins
allow the cell to receive instructions

10. Active Transport
Carrier Proteins- They do not extend through the membrane. They bond and drag molecules through the bilipid layer and release them on the opposite side.
Movement from low concentration to higher concentration. Requires energy input.
Animation

11. Passive Transport
In some cases the channel proteins simply act as a passive pore. Molecules will randomly move through the opening in a process called diffusion. This requires no energy, molecules move from an area of high concentration to an area of low concentration. Ex. CO2 and Oxygen
Animation

12. Endocytosis
Is the process by which cells engulf large particles by extending their cytoplasm around the particle.
Two types: phagocytosis, pinocytosis
Animation

13. Exocytosis The opposite of endocytosis is exocytosis.
Large molecules that are manufactured in the cell are released through the cell membrane.
Animation

14. Homework Read pp79-84 Page 88 #18 Page 89 # 28,32
List three factors that alter diffusion rates
Why does grass wilt if it is over fertalized?